Kyiv and Ukraine: 1564-1795
The word 'ukraine' means 'borderland' in proto-Slavic languages. It turns up as early as 1187 in a Kyivan Chronicle, in the sense of 'borderland'; so where the population of one polity thinned out to uninhabited Steppe and fronted another polity, they could each refer to their borderland or their 'ukraine'.
However, by early 1600s maps were appearing with the capitalised proper noun Ukraine. Thus "Vkraina" and "Kyovia" turn up together on the Radziwill map of 1613. In mid seventeenth century, Guillaume Le Vasseur de Beauplan, a French cartographer working for the Polish army, published a map of "Ukrainska" in 1635 covering the area from the river Don in the east to the river Dniester in the west, and from Kyiv south to the Black (or Euxine) sea. His book Description d'Ukranie of 1651 was very widely read and republished in western Europe.
Bohdan Khmelnytsky (1595 - 1657)
(This section is the expansion of a paragraph in my post Kyiv3 it tells how, in an effort to free itself from Polish control, what we now think of as Ukraine passed into the control of Moscow.)
Born c. 1595, Chigirin, Ukraine
Died 1657, Chigirin. (Aug. 16, [New Style])
Khmelnytsky was the leader of the Zaporozhian Cossack rebellion (1648–57) against Polish rule in Ukraine that ultimately led to the transfer of the Ukrainian lands east and south of the Dnieper River from Polish to Russian control. In summary: the revolt, with the taking of Kyiv and Lwów, was initially successful but, after repeatedly being let down by the Islamic Crimean Tartars, Khmelnytsky made a treaty with the Russians (1654).
Although Ukrainian born, Khmelnytsky had been educated in Poland and had served with Polish military forces against the Turks. He had become chief of a Cossacks regiment at Czyhryn (Poland), but quarreled with the Polish governor there and fled (December 1647) to the fortress of the Zaporozhian Cossacks, a semi-military community that had developed from runaway serfs, bandits, and traders who had settled along the Dnieper River (Zaporizhzhia="below the rapids"). There he organized a rebellion among the Zaporozhian Cossacks and, with the support of the (Islamic) Crimean Tatars, marched against the Poles in April 1648. His victorious advance into Kyiv won him additional support from the dissatisfied peasants, townspeople, and clergy of Ukraine, who joined him in a mass uprising that enabled him to enter Poland proper and seize Lwów (now Lviv) in October 1648.
After winning more victories in 1649, Khmelnytsky made peace with the new Polish king, John Casimir, concluding the Compact of Zborów (Aug. 18, 1649); its terms permitted him to establish a virtually independent Cossack principality in Ukraine.
That treaty, however, satisfied neither the Polish gentry nor Khmelnytsky’s followers. He therefore renewed the war in the spring of 1651 but was defeated at the Battle of Beresteczko in June 1651 and was compelled to accept a new, less advantageous, treaty.
In the face of a growing threat from Poland and forsaken by his Tatar allies, Khmelnytsky asked the the tsar of Russia (Tsar Alexis) to incorporate Ukraine as an autonomous duchy under Russian protection. The Russians were reluctant to enter into such an agreement, and it was not until October 1653 that they approved the request and Tsar Alexis sent a delegation to the Cossacks.
Pereyaslav Agreement Only after the Cossacks had suffered a further disastrous military defeat (December 1653) did they receive the Muscovite delegation at Pereyaslav and formally submit to “the tsar’s hand.” Two months later (March 1654), the details of the union were negotiated in Moscow. The Cossacks were granted a large degree of autonomy (under a Cossack 'Hetman'), and they, as well as other social groups in Ukraine, retained all the rights and privileges they had enjoyed under Polish rule. But the unification of Ukraine with Russia was unacceptable to Poland. It launched the Russo-Polish war ("Thirteen Years’ War") which ended (1667, Truce of Andrusovo see below) with the division of Ukraine between Poland and Russia, along the Dniepro river, but with Kyiv allocated to Russia .
Early in the Thirteen Years’ War, the Russians invaded Poland, but Khmelnytsky, not content with his pact with Alexis, entered into secret negotiations with Sweden, which was also at war with Poland. He was about to conclude a treaty with the Swedes, placing the Cossacks under Swedish rule, when he died (1657).
Khmelnytsky had sought autonomy for his Cossack followers but succeeded only in devastating their formerly flourishing Dnieper lands and in subjecting them to the rule of Moscow, which gained control of Ukraine east of the Dnieper and gradually curtailed their liberties, until in 1764, when Catherine II (the 'Great') of Russia abolished the 'Cossack Hetmanate'. (See my post Kyiv 4).
The Truce of Andrusovo (1667) established a thirteen-and-a-half year truce, signed on 9 February [N.S.] 1667 between the Tsardom of Russia and the Polish–Lithuanian Commonwealth. That this war trailed on for 13.5 years shows that neither side was vastly more powerful. In 1610, Poland had invaded Russia, captured Moscow, and taken the Tsar (Vasili IV) back to Poland in a cage. But this truce seems to have tipped the balance from Poland to Russia.
[Based on several articles in Encyclopedia Britanica and Wikipedia]